Fuel Cell System Startup Temperature Control
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Solution Overview
Problem
The existing fuel cell systems face excessive temperature rise during startup due to oxygen being in excess compared to fuel gas, which can deteriorate the reforming performance of the fuel processor.
Innovation Solution
A fuel cell system control method that adjusts the flow rates of fuel and cathode gases to prevent excessive temperature rise by controlling the supply of cathode gas and fuel gas, ensuring the outlet temperature of the fuel processor remains within a safe range for efficient reforming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cathode gas is supplied before fuel gas to warm up the fuel processor, then the fuel processor reaches reforming temperature faster, but excessive temperature rise occurs due to oxygen being in excess compared to fuel gas
Solution Approach 1:
The patent applies dynamics by making the cathode gas supply flow rate variable rather than constant. The control device dynamically adjusts the cathode gas flow rate based on real-time temperature measurements from the temperature sensor, increasing flow rate when temperature is low and decreasing it when temperature approaches the target range, thereby preventing excessive temperature rise while maintaining efficient warming.
Solution Approach 2:
The patent implements feedback control by using a temperature sensor to continuously monitor the fuel processor temperature and feeding this information back to the control device. The control device then adjusts the cathode gas supply accordingly, creating a closed-loop control system that automatically prevents overheating while achieving efficient warming of the fuel processor.
2Object-affected harmful factors
If cathode gas supply is reduced to prevent excessive temperature rise, then temperature control improves, but warming efficiency decreases
Solution Approach 1:
The patent resolves this contradiction by dynamically adjusting the cathode gas flow rate based on real-time temperature conditions. During early warming stages when temperature is low, the cathode gas flow rate is maintained at higher levels for efficient warming. As temperature approaches the target range, the flow rate is dynamically reduced to prevent overheating, thus maintaining both warming efficiency and temperature control.
Solution Approach 2:
The patent applies periodic action through staged control of cathode gas supply. The control device operates in different phases: initially supplying cathode gas at higher rates for rapid warming, then transitioning to reduced rates as temperature targets are approached. This periodic adjustment pattern optimizes both warming efficiency and temperature control throughout the startup process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively suppresses excessive temperature rise during startup, ensuring the reformer operates within optimal conditions, thereby maintaining the reforming performance and preventing damage to the fuel processor.
Implementation Method 1
POX (partial oxidation) reforming is performed when the cathode gas is supplied before supplying a fuel gas
Implementation Method 2
a fuel cell system that suppresses excessive temperature rise during the warming processing at the starting-up of the system
Implementation Method 3
sequentially implementing a POX operation, ATR operation, and SR operation
Implementation Method 4
sequentially implementing a POX operation, ATR operation, and SR operation
Data Source
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AI summary
According to a control method of controlling a fuel cell system, the fuel cell system including a solid oxide fuel cell that is supplied with an anode gas and a cathode gas to generate electric power, a fuel processor that at least reforms fuel to generate the anode gas and supplies the generated anode gas to the fuel cell, and a combustor that combusts the supplied fuel to perform warming of the fuel processor, the method is conducted when warming is performed at least at starting-up of the system. The method comprising: a cathode gas supply step of supplying the cathode gas to the fuel processor; a determining step of determining whether a temperature of gas passing through the fuel processor is higher than a temperature at which reforming is possible; a cathode gas decreasing step of decreasing a supplied amount of the cathode gas to the fuel processor when it is determined that the temperature of the gas is higher than the temperature at which reforming is possible; and a fuel supply step of supplying the fuel to the fuel processor.